The only markers I apply to determine whether someone is a woman is their biological status. Applying any other markers is sexist.
I look at a person wearing jeans, docs, a hoodie, short hair. They could be male or female. I look at someone who is at home minding their children. They could be male or female. I look at someone working as a plumber. They could be male or female. I look at someone working as a nurse. They could be male or female.
Why are TRAs trying to reverse decades of work that achieved some level (but still a lot to go) of equality of opportunity? Why do they want women and men to be pigeon holed into caricatures of woman/man?
This is all taking the statement out of it's context, which is medicalized and only relevant in a situation where the person in question is not, in fact, a woman.
I'm about as critical of gender ideology as you can be, and I think it does tend to lead to sexism because of the larger implications, but it is not really useful to treat this statement in a way that completely decontextualizes it.
It's not asking you to say that only women can be nurses, or they can't wear hoodies. But I don't really believe that anyone doesn't recognize that William is usually a male name and Sue a female name, or that we have pronouns associated with our sex, or that there are some clothing and fashions that are more associated with one sex than the others. That's not what a stereotype is. And I would maintain that these female associations are not somehow "lesser" than the male ones.
If a person who is male is using titles or language usually associated with women, and taking on other cultural customs associated with women, there is a sense in which they are doing something different than what is usual, and in a deliberate way. Saying that none of those things makes someone a woman doesn't make that less true.